table t (x varchar2(8));

Table created.

secooler@ora11g> insert into t values ('Secooler');

1 row created.

secooler@ora11g> commit;

Commit complete.

secooler@ora11g> select * from t;

X

--------

Secooler

2)此时观察ora11g实例的alert日志记录了如下信息

Fri Mar 16 11:56:36 2012

create tablespace secooler_tbs datafile '/u01/app/oracle/oradata/ora11g/secooler_tbs01.dbf' size 10m

Fri Mar 16 11:56:48 2012

Completed: create tablespace secooler_tbs datafile '/u01/app/oracle/oradata/ora11g/secooler_tbs01.dbf' size 10m

3)几乎与此同时(1秒)备库ora11gdg实例的警告日志中记录了如下信息

Fri Mar 16 11:56:37 2012

Recovery created file /u01/app/oracle/oradata/ora11gdg/secooler_tbs01.dbf

Successfully added datafile 5 to media recovery

Datafile #5: '/u01/app/oracle/oradata/ora11gdg/secooler_tbs01.dbf'

可见，备库已经接受到主库的这个变化，并把这个变化在备库应用完毕。

4)验证主库所创建表空间、用户以及表并初始化数据是否在备库应用成功

(1)查看备库表空间

sys@ora11gdg> select * from v$tablespace where name = 'SECOOLER_TBS';

TS# NAME                           INC BIG FLA ENC

---------- ------------------------------ --- --- --- ---

8 SECOOLER_TBS                   YES NO  YES

sys@ora11gdg> select ts#,status,bytes,name from v$datafile where ts# = 8;

TS# STATUS       BYTES NAME

---------- ------- ---------- ------------------------------

8 RECOVER   10485760 /u01/app/oracle/oradata/ora11g

dg/secooler_tbs01.dbf

创建成功，但是此时备库数据文件的状态是“RECOVER”。

(2)查看备库用户及数据是否存在

sys@ora11gdg> conn secooler/secooler

Connected.

secooler@ora11g> set lines 80

secooler@ora11g> desc t;

Name               Null?    Type

------------------ -------- ----------------------------

X                           VARCHAR2(8)

secoolerdg@ora11g> select * from t;

X

--------

Secooler

主库上的变化已经即使的在备库上得到应用。

这便是Oracle 11g物理Active Data Guard实时查询(Real-time query)特性的体现。

3.小结

本文以